Outfeeding means for fuel pulverizing machines



Oct. 20, 1931. P. A. HIRSCH 1,828,712

OUTFEEDING MEANS FOR FUEL PULVERIZING MACHINES Filed June 1; 1926 2Sheets-Sheet 1 INVENTQR 1 mm. 9 wank T s K K Whdl A'i'TORNEYS,

Oct. 20, 1931. P, A. HIRSCH OUTFEEDING MEANS FOR FUEL PULVERIZINGMACHINES Filed June 1, 1926 2 Sheets-Sheet 2 INVEN TOR @my y 81MMKATTORNEYS Patented 20, i j I i I p j OUTEEE I NG MEANS tonrwreerwmzimMACHIN S I A p ication elea iirim jr, nae/ser l No: 1 12356. v

This invention is a novel outfeedin'g means Fig. "4;is a partialperspective view of'a for pulverizing machines, having referenceperipheral portion- Of -the r tary fan or particularly tothe pulverizingof coal, or flower.-

-' q a i other fuels. The invention-is herein: shown Referring in;detail to the illustrated struc- 5 embodied in" a type of'pulverizingmachine ture 1F i'gxl shows a pulverizingmachine of having a chamberedcasing, with an .operat' the horizontal type, the same as my aforesaidnig shaft therein, and impact 'beatersfior Patent 1,479,540, although insome cases it paddles revolved by the shaft, while axial air could aswell be arranged vertically as'in my flow causes progressive advance oft-he m'aother Patent 1,479,541 of the same date.

" 1o terial. being reducedyalthough features of Mounted ona-base11isshown a cylindrical M the present invention may be otherwise emdrum orcasing 12' preferably lfixed againstbodiedr A prior pulverizer of thetype and rotation. The drum may be-constructed'in for the purposereferred to, isillustrated in two orthree radially divided sections forthe my Patent No. l',479,540=of. January'1, 1924. purpose of assembly,disassembly and trans- One of the main objects ofthe presentinportation; The lower right'hand part of the vention is to improve thedelivery-of the pul casing is shown as having a' dropped extenverizedmaterial from'the machine, namely sion;14 in: which foreign material maybe colinto a delivery or fan chamber, and the dis-i lectedaswill bedescribed,ra removable'cover charge thereof from the fan chamber,-and inorfrece'ptacle15 being attached to the open '35. the'case of fueltheadmixturethere'ofwith side of the "extensionby which the foreign I 35described.

5 or blower.

additional quantities of air- 0f combustion;- I material "may be removedfrom timeto time. thisinvolving a novel-structure of delivery The{drum'or casing encloses successive chammeans or fan and thenovel'method'or mode bers' or spaces and is shownv as lined :with a ofoperation secured thereby. v steel lining'or'ring '17 in each of-thepulver Other and further objects andadvantages i zing spaces orchambers, the right hand-one of the'present invention will beexplained-in 'of these linings being perforated at 18 above thehereinafter followingdescription of an the extension 14 to permit heavyand foreign illustrative embodiment thereof, or wi1lbe material .to bedischarged from the chamber v apparent to those skilled in-the art. :Tothe into the extension. V a v 7 30 attainment of the objects andadvantages The-drum at'its right end is closed by a cirreferred to thepresent invention consists in cular end-wall or casting or head 19having a the novel method and machine, and the; novel central or axialopening 20- by which the-mafeatures of operation, combination, arrange:terial to, be-pul-verized'can enter the drum. I ment andconstructionfherein illustrated or The head l 9 is shown formed with aneXten' I v a x 5 I; fi vsion2'1,' the lower part of whichis inclined Inthe accompanying drawings. Fig-ul' is so as to facilitate the infeed'ofmaterialto' the substantially "a central vertical cross section'pulverizer and the d scen of heavy-for ign v of a pulverizing machineillustrating; the materials'toward the extension-14; The eX" presentinvention, the fuel and air infeed tension-21 m further shown as givingsupport g 40 shown at the right end and thedelivery means to one of thebe'arin gs 24 of I the 1 operating at the left end'of-thelfigurefl I 1shaft the'other end of the shaft hav- Fig. 2 is a detail perspectiveviewshowing 'ing. a similar bearing 26 supported upon one of thepulverizingmembers, beaters or a fixed? frame extension {or bracket 33.paddles OfthiS inventiomand its relation to The driving shaft 25' may berotated at high the fast rotatingwheel or-fdisk whichcarries speedthrough its exterior'extension 28 in any it. 3 desired mannerQforexample through belt Fig. 3 is a right elevation takenpa'rtlyin and:pu'lley'or direct. coupled motor, turbine section onithe line 3-43of-Fig.'-1:and showing or the like. I u I 1 the preferredconstruction ofthe delivery "fan The left or discharge end of the drum is r +5 shownasclosed by an'end wall or head 29 side the drum, while the air draftfor the final discharge and dilution of the pulverized materials isprovided by a suction fan or blower located beyond the pulverizingchambers, and exterior to the pulverized discharge wall or head 29. Forthis purpose a fan cas-. ing 31 is shown, which may conveniently beintegral with the head 29. The bracket support 33 for the bearing 26 mayalso be in? tegral with the fan casing. The fan casing has alsoaperipheral extension 34 providing a tangential exit passage or discharge35, analogous to that shown in said prior Patent 1,47 9,540, but hereinshown directed upwardly, as is frequently necessary for blowing out ordelivering-the mixed fuel and air toa furnace.

The infeed of the fuel may be by a hopper 37, suitably supplied withcoal or other material after preliminary grinding to a suitable size.The hopper 37 loads to a regulatable feed comprising a rota-ted starwheel 38 bringing successive fuel portions into the following passage39, the materials passing downwardly by gravity into the separatingchamber 41, the walls 42 of which may be integral extensions of thecasting 21 containing the central inlet aperture 20. One of the walls 42may contain an opening 43 forthe admission of air, and it will beunderstood that any of the air admission opening or ports may beregulatable by a damper. \Vithin the chamber 41 may be any suitableseparating means such as a magnetic shell 44 turned continuously by ashaft 45, these parts indicated in dotted lines. Electromagnets withinthe shell may maintain a condition of strong magnetism so that all ironparticles will be caused to adhere strongly to the shell and thuscarried around to the outer portion of the chamber, where they areprogressively detachedfrom the shell by the scraper or flange 46, thusdepositing the iron particles in the receptacle 47 from which they maybe removed through the aperture 43. The shafts of the star feed wheel 38and of the magnetic shell 44 may be suitably driven in ,synchronismduring the operation of the pulverizer, and the speeds may beadjustablein any usual manner to regulate the rate of fuel feed, a slower rate offeedbeing accompanied by a greater degree of pulverization.

The fuel passing through the separating chamber 41 descends into thepassage 48 in the extension-21, a plate 49 acting as ashield to insurethe materials entering with adescending motion or preventing theirentering into the first pulverizing chamber above the operating shaft.

There maybe a single pulverizer chamber within the drum, or a series ofthem, and Fig. 1 shows a first reduction chamber 51 and a secondreduction chamber 52, within which the fuel will be progressivelypulverized by the fast rotating heating means mounted within eachchamber upon the shaft 25. Thus the shaft is shown as having pinned orkeyed to it in each chamber a hub 54 on which is mounted a disk 55,around the circumference of which are mounted a series of-peripheralbeaters or paddles 56. Such a beater structure has been alreadyexplained'in said prior patent, although the structure of the beaterhereof is considerably improved with resulting increase of efliciencyand length of life, as will be explained.

Located between the first and second pulverizing chambers 51 .and 52 isshown a means for effecting a sudden obstructing of thewhirling.motionproduced by the fast rotating paddles in chamber 51. Thiswhirl obstru'ctor may be in the form of a series of blade-like vanes 60set edgewise to the axial advance of the material and extending from ornear the periphery of the chambers to or toward the shaft. Preferablythe vanes 60 are relatively stationary, and they may stand radially orotherwise. The action of such vanes has been described in said priorpatcut. The several vanes may be mounted and interconnected by means ofa peripheral ring 61 attached to the lining 17, and an inner ring 62loosely surrounding the shaft 25.

Beyond the second pulverizing chamber 52 and between it and the fancasing is shown another set of obstructing vanes 65, with an outer ring66 interconnecting them. These have a special function herein, inaddition to the function possessed by the vanes 60; this to be explainedmore fully hereinafter. An inner ring 67 unites the inner ends of 65. Itwill be noticed that within and between the pulverizing chambers thereare no annular or other division walls or so -called diaphragms, nor anysubstantial obstruction to the axial progressof the materials, betweenthe axial entrance aperture 20 in the head 19 and the axial exitaperture 30 in the head 29. This aperture 30 is of considerably lessdiameter than the pulverizing chambers, and of less diameter even thanthat of the pulverizing elements, that is, the diameter from tip to tipof the paddles. In these and other respects to be explained the presentinvention is materially difi'erent from said prior patent and otherprior structures of which I am familiar; The aperture 30, indeed, isshown of su'ch'small diameter that materials progressing through it passinto the interior of the rotary fan structure, an importantconsideration. I

The 'fan chamber 32 may be almost of the full diameter of the maincasing, as shown, but the fan 7 0 is preferably of considerably ma ma: p

' smalleridiameterf Itis' shown'm'oiintedson a hub 71 keyed tothe'jshaft-2'5.. A znovelsand efficient fan construction isshown whereinthe hub 71 carries a disklor circularrplate 7 2, p posite to whichiisail-ing or annularplate73, the disk and the ring. supporting, and beinginterconnected by, a series of fan blades 74; With this invention theblades 74 are" ar-i ranged to'handle the supplemental air of com:bustion-which may be introduced'intothefan ,chamber 32 by way ofthe-axial inlet '36,

I whichmaybe damper governed,=the air being on the disk nearitsperiphery by means ofv an outer bolt or pivot 78, the plateformed with aconcentric slot 79 engaged by an inner bolt 80 engaged in a,threadedperforation 81 in the disk... By this. arrangement the .fuel

whirling fan blades 76 may be adjusted in their angle and operation.Figs. 3 and' i'show two different angular adjustmentsof these.members,while Fig. 3'in dot-and-dashdines shows the two extremes of adjustment'as pref erably used.' It will be observedthat the fuel jwhirling blades 76 are slanted from the ra dius, whereasthesupplementalair whirling blades 74 are preferablyradial; The slant-oftheblades 76, and themeans ofadjustment thereof, aflordanadvantageousaction as will I bedescribed. a i. The paddles, hammers orbeaters,56' are. herein constructed and mounted in a novel manner givingsubstantial advantages. In the hammer-mounting of'said prior patents thecontinuity of the surfaces of thesupport ing disks issubstantiallyinterrupted near the periphery by protruding portions ofthepad clles and the bolts by which they areinounted. 'By comparativetests it has been found that these protruding elements are not merely'the source of wear and expense, but owing to their being in thepath ofthe centrifugally flowingpowdered materials they cause a dis-'- turbanceof the flow and impair the efiiciency of the reducing'action; Theseobjections are Wholly overcome by thepresent construction in which thesides of'the disk are uninterrupted by protrusions and the whirl I ingmaterials are able to pass'smoothly outwardly intothep aths of thebeaters or pad dles, rendering the beating action more 'thor oughand-actually resulting in a greaterfineness of pulyerization andincreased capacity of the machine, with reduced power.

-- :l-Tlie paddlesioribeaters are, llowances relative:v arrangementinFig. I 1, and .the -preferrdt details of; structureiin Fi'g.;f2". Each Qpaddle comprises'aLT-shape body '85,--1nounted preferably swingablyatlthe periphery of the disk 55 The enlarged-portion"o nhead of thepaddle body 85 is formedwith an outer flange I 86, and aremoyable'paddle face plateor block 87"Iis-..provided with a shoulder88: engaging the'fiange 86, giving an -interlo'ckingaction,

andienabling the centrifugal thrust :ofgthef l blocks87 to bereceived'b-y Itheflange'SG with-J out anyv shearingstrain upon the bolts89 by which the blockis secured fiOE-thG body... The

forward side orjface' 90i-ofthefblock 87*is shown'incline'dforwardlygiving an-efi'ective beating action andallowingfor wearby'abra'sion'at a greater rate near lthe periphery of thelblock withoutsubstantially impairing theeffectiveness of theaction'lf'The thin-webportion 91 ofthe paddle body 85 is perforated andin use is arranged'inla irece'ss'in the}pe-; riphery of the disk 55, so-"as not to protrudebeyondthe flush surfaceof. the "disk This recess ispreferably in theform of, a kerf 92, and there may be a separaterecessor kerf for 1 eachofthe paddles or-there maybe. a continuous kerf orgrooveextendinghentirely around the peripheral edge of the disk 55.

by means of a trans verselstud 93,-whichmay be a simple pin without headat-either' end, and this stud in turn maybe held againstdis- 1placementby a cotter pin"94,'screw or other means securing it to theweb' 91; of the. paddle. Instead of a single integral disk 55 providedwith' an edgegrooye or kerf 92, this disk may be builtiup, for exampleby two circular plates spaced'slightly apartto accommodate faceiplatesor blocks 87 which are readily" renewable, so that the lifeofthecapparatu andthe ease of renewal'a-re greatly enhanced.

Not only is efiiciency increased,- as explained,

but the first cost" of the machine is reduced,

since the renewable face block 87 maybeicoin' .7 1

posed-*of' hard steel While the paddle body 85 mfayjbe o-f'cheapermaterial as a lower gradei 0 steel; i v

1 In operation themachinecombinesa regus lated air and coal "feed at oneend and at'the other end a suction fan oflow 'pressureand 1 5 powerreceiving thepulverized materials and discharging themcentrifugally. Inthe'first pulverizing chamber 51 anymetal and otherheavymaterialnotremoyed in the separat-ing' chamber will be thrown downcentrifugally 1 .into the extension-'14. The entering-fuelfis v The web91 is heldin placein the kerf 9 2 faces take the brunt of thereduc'ingEaction,

and these two elements arereadily and cheaply replaceable. Succeedingthe first reducing chamber are the fixedv vanes which totallyobstructthe whirling motion while permitting substantiallyuninterrupted. axial progress. Pulverizing occurs at this point, notmerely by the impact of the fast whirling particles against the fixedvanes but by;rub

bing and attrition along the surfaceof the vanes and moreoverby anaction of throwing back of the heavier particlesinto-the reducingchamber, permitting only the finer particles to progress, asexplained-in said patent.

Passing from the vanes 60 the materials under treatment are again thrownsuddenly intowhirling motion and are furtherreduced by impact andattrition. The peripheral surface of-the interiorof the apparatus issubstantially free from. obstruction to axial progress. There are. norings or diaphragms and the high centrifugal pressure ismaintainedthroughout the length of the mill upto the point where the'reducingaction is completed. At this point'the vanes-6f)- 0p: erate to overcomethe .centrifugal pressure and permit the whirling mattersto be drawninwardly to the contracted-outlet 80. The dynamic energy of the whirlingmatters striking against the stationary vanes causes them to spread soas: to reach the outletaperture. In effect the-centrifugal action isconverted to a centripetal motion. 7 The end wall 29'acts as-a dam so asto confine the fan. or one of the full diameter of the paddles mightresult in excessive pressure or suc-. tion and tend to extract thewhirlingmatters from the main-casing faster than is consist ent withefliciency and fineness of reduction,

fourths. of the diameter of the reducing devicesgives satisfactoryresults. It keeps the air and materials, in progress but avoidsex:cessive suction. Maximum internal centrifugal'pressureis thusmaintainable, the divertingvanes65 operating to bring themater-ialstothe outlet, andthe fanoperating upon them for finalcentrifugal discharge. This refers to the blades 76 and one featurethereof is their relativelyfsmall size and their adjustability ofangle.I

The disclosed fan-as a discharge means for a pulverizingmill can beadvantageously used with other types of mill than the impact millhereindisclosed, for example with ball mills, roller mills. One duty of suchfan isjto 'niaintain-the progress of'the whirling matters, coal dust orother material in suspension in air, through the pulverizer and itsoutlet, and a second duty is to deliver these materials-to the furnaceor other place of use, and frequently to provide and mix therewithsupplemental air of combustion. These two functions are in some respectsquite dif- 'ferent and the best results are found to be attainable byaseparation of functions as herein disclosed, enabling the materialsbeing treated to behandled and discharged separately from thesupplemental air. A low suction and pressure isldesirable for the coaldust :or other material, especially when the interior ofthe main casingis progressively cleared for example as alreadydescribed inconnectionwiththe vanes 65.. On the other handthedelivery of the coaldust and air intoca furnace demands enough pressure to overcomethevresistance of the burners and piping, with some sparepressureto regulatedistribution. The present invention gives satisfactory .results .forboth purposes and this is effected moreover by the novel fan hereofoperating in the usual type of fan housing annexed to the pulverizeroutlet. The fan chamber, except near the periphery and discharge, iseffectually divided into separate chambers by the unperforated disk 72.At the pulverizer side of this disk is what may be termed: the dustchamber and at the other or outer side the air chamber. Operating in theair chamber are the whirling blades 74- which operate to draw airinthrough the axial inlet 36 "and throw it centrifugally out through thedischarge 35, with relatively high pressure andzrate of flow. The solidmaterials or'dust never reachesthe air chamber or contacts the airblades, but is, handled entirely separately in the dust chamber. Theremovable dust blades 76 thereby take all the'brunt ofthe wear from theprogressing solid materials; enablingthe fan to be renewed by merelyreplacing these parts, thus greatly minimizing upkeep expense. 2

The swivelled attachment of the dust blades 76 permits the suction andpressure lhave. found that afan of not over threeto be'adjusted to the.conditions. Expert.

' ments have indicated that the nearer the put.

' chamber into two subchambers and the separation of the functions ofthe fan as deblades 76 are set to a tangential position the finer willbe-the pulverization. 1 Thus the adjustment shown; in Fig. 4: givesslower discharge and finer pulverization than that shown in Fig. 3,which will result in coarser pulverization but increased capacity ofout- The arrangement thereby permits the machine to be adjusted inaccordance with the material being ground and the desired fineness ofproduct, the angle of the dust blades to be set to themost advantageousangle.

It will be observed that the adjustment of the dustblades and theresulting discharge of dust does not affect the dischargeof air by theair blades 74. dependent up to the pointv where the discharged mattersmeet and mix in the general discharge outlet 35. The division of the fanscribed may be brought about in various ways. The dust tegral extensionsof the air blades, and the disk 7 2 adjusted axially. to relativelyincrease blades the feedingaction of 5. A fan as in claim (l. andwherein the disk, air blades,and dustblades constitutearotor The twoactions are 1n-v blades could be made as .in-

project laterally, with means for ad usting consist of angle piecesarranged to their-angular relationship to the air blades.

LA fan for feeding V comprisinga casing, a shaft rotatabletherepulverized material,

in, a disk on the shaft separating the interior of the casing into adust chamber and a" wider air chamber,

"radially disposed air blades secured to theairside of the disk, and Iif nonradial dust blades secured to the opposite side of the disk, saiddust blades being adjustable to different angles whereby to vary= thefan.

of considerably smaller diameter than the-' interior of the casing.

In testimony whereof, I have aflixed if signature hereto.

PAUL- ARTHUR iinason;

V I the sizeland actionof the dust blades and dea,

' plemental air, or

. crease those of the air blades,

; pulverizing action.

ment of air flow or discharge by the, fan would cause a change in thefuel outflow and thereby alter the actions within thepulverizer whereapulverizing machine principles and attaining the objects of theand viceversa. 'It is to be understood that dampers may be employed to regulatethe admission of sup-- tions can be made without affecting theOrdinarily ,an a

as with the present invention even very hlgh the flow of the combinedmaterials to the furnace, and such reguladjustair pressures can besupplied for distribution to combustion points without substantiallyaltering the constancy of the action" and progress through thepulverizer. 1

. Itwill thus be seen that I have; if

embodying. the

of the disk and air blades at the opposite side I of the disk, the dustblades being angularly I disposed with reference to the air blades.

2. A fan asinclaim 1 and wherein the'dust v blades are detachable andremovable independently of the air blades.

' v 3. A fan as in claim l and'wher'ein the dust

